I read instructions online that said I could get all of my POP3 e-mail on my iPhone 5, desktop PC and laptop PC as long as "Leave a copy of e-mail on server" was checked on both computers (there is no way, I'm told, to do that on my phone since it's done by default). It does not work. Can this be fixed without deleted my POP3 account and adding an IMAP account which seems to risk losing previous e-mails?